Harper
Harper is a Rust-based application that provides grammar checker that analyzes your writing quickly while keeping your data completely private.
Overview
Offline, privacy-first grammar checker. Fast, open-source, Rust-powered Harper is a blazing-fast, open-source grammar & spell checker that runs entirely on your device, covering US, UK, Canadian & Australian English—no data ever leaves your machine. Harper is the only grammar checker that doesn’t use AI. The project has 10K+ GitHub stars and is licensed under Apache-2.0.
Normalized Features
Source: tool-features-normalized.json
plugins.
Deploy
Features
Integrations & APIs
- Plugin / Extension System
Category
Replaces
Related Office & Productivity Tools
View all 75 →
Excalidraw
119KOpen-source virtual whiteboard for sketching hand-drawn style diagrams, wireframes, and architecture charts — collaborative and end-to-end encrypted.
reveal.js
71KThe open-source HTML presentation framework — create beautiful, interactive slide decks using HTML, Markdown, or a visual editor, with 70K+ GitHub stars.
tldraw
46KInfinite canvas whiteboard with real-time collaboration. Embed in your app as a React component or use as a standalone drawing tool. No signup required.
Penpot
45KPenpot is the open-source design and prototyping platform that bridges designers and developers with web-native standards, real-time collaboration, and no vendor lock-in.
Onlook
25KOpen-source desktop app for visually editing React applications with changes written back to code in real-time.
Graphite
25KOpen-source 2D vector and raster editor with a nondestructive, node-based workflow that runs in the browser.